Eminem won a case against the National party in New Zealand in October last year.
Photograph: RMV/REX/Shutterstock

The National party in New Zealand is refusing to move on from its copyright fight with Grammy award-winning rapper Eminem, arguing a decision by the high court ordering it to pay the singer NZ$600,000 ($400,000) is too high.

In October last year New Zealand’s high court ruled that the National party infringed on the singer’s copyright when it used refrains from his song Lose Yourself in a campaign ad. The court awarded the rapper’s publisher NZ$600,000 in damages.

The advertisement featuring a track called Eminem Esque was played 186 times on television during the 2014 election campaign over an 11-day period.

The court ruled on 25 October that the National party’s use of the track was “sufficiently similar” to Eminem’s original song that it impinged on copyright and that Lose Yourself was a “highly original work”.

On Tuesday National party’s lawyer Greg Arthur appeared in the court of appeal to argue the penalty imposed by the high court was too harsh, and the “hypothetical license fee” of NZ$600,000 was not proportionate to the breach as the advertisement only played on New Zealand television, Newshub reported.

The outcome of the appeal has been reserved, meaning it could take weeks or months for a decision.

The October ruling last year stated: “Eminem Esque has substantially copied Lose Yourself.

“The differences between the two works are minimal; the close similarities and the indiscernible differences in drum beat, the ‘melodic line’ and the piano figures make Eminem Esque strikingly similar to Lose Yourself.

“Eminem Esque substantially reproduces the essence of Lose Yourself. The parts of Eminem Esque used in the National party’s campaign advertisements also substantially reproduce Lose Yourself.”

Lose Yourself, from the movie 8 Mile, won an Academy award for best original song in 2003 and a Grammy for best rap song in 2004.